This invention relates to the prevention of access of bacteria and other contaminants to an area where medical operations are carried out.
In my copending application I have disclosed that bacteria and other contaminants can be denied access to such an area by directing a stream of sterile gas over the area to act as gas curtain which prevents access of such contaminants to the area.
That arrangement has been found to be largely satisfactory in its intended effect. However, I have observed that there are some ways in which contaminants may still penetrate the gas curtain.
In particular, in the area where the stream of sterile gas issues from the outlet opening that is provided to direct it across the operating area, there is the danger that the sterile gas stream aspirates contaminants from the ambient space into its boundary layer from where they can make their way to the protected operating area. Contaminants may also enter from the area below the top of the operating table, making their way around the edge of the operating table top and then being picked up by gas eddies to be carried to the operating area.